[gtk+] Add a missing include

[Matthias Clasen <matthiasc src gnome org>]

commit 453849acf372ac0c49cb4a1e392665e964e74fae
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Jun 7 18:37:36 2011 -0400

    Add a missing include

 gtk/gtktreestore.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtktreestore.c b/gtk/gtktreestore.c
index a1a91c2..e2e969e 100644
--- a/gtk/gtktreestore.c
+++ b/gtk/gtktreestore.c
@@ -25,6 +25,7 @@
 #include "gtktreedatalist.h"
 #include "gtktreednd.h"
 #include "gtkbuildable.h"
+#include "gtkdebug.h"
 #include "gtkintl.h"